Sea Angels Arrive at Moscow’s Moskvarium in Rare Deep-Sea Exhibition

The Moskvarium at VDNKh has unveiled one of the ocean's rarest and most delicate inhabitants — translucent sea angels from Arctic waters that appear to "fly" underwater.

Rare winged mollusks known as sea angels have arrived at the Moskvarium at VDNKh, giving visitors a rare opportunity to observe one of the ocean's most unusual inhabitants.

According to the aquarium's press service, sea angels are among the most extraordinary creatures in the marine world. Encounters with them are exceptionally uncommon: they inhabit cold northern waters and usually live at considerable depths, while their short life cycle allows them to be observed for only a few months each year.

Sea angels received their poetic name because of their transparent bodies and delicate wing-like appendages, which create the impression of a celestial being drifting through the water. Their graceful movements make it appear as though they are floating rather than swimming.

"Sea angels, or Clione limacina, are winged mollusks descended from a common ancestor shared with modern snails,” representatives of the Moskvarium explained. "During evolution they developed two translucent wings that seem to be woven from light itself. Using them, sea angels trace figure-eight patterns in the water, much like butterflies moving through the air.”

Scientists note that such elegant locomotion is remarkably sophisticated for an invertebrate species.

The mollusks are being housed in a specially equipped aquarium recreating the cold-water conditions to which they are naturally adapted. Over the coming months, researchers from the Russian Academy of Sciences together with specialists from the Moskvarium will study the rare species.

Sea angels are native to Arctic and sub-Arctic waters, including the White, Barents, and Bering seas. Despite their fragile appearance, they are active predators and primarily feed on another tiny mollusk known as the sea butterfly.

Unlike most mollusks, sea angels lose their shells during development and become almost completely transparent as adults. This natural camouflage helps them remain nearly invisible in the open ocean.

Opened in 2015, the Moskvarium is one of Europe's largest oceanography and marine biology centers. Located at VDNKh in Moscow, the complex houses thousands of marine and freshwater species from around the world, including sharks, rays, dolphins, beluga whales, jellyfish, octopuses, and rare Arctic organisms.

The center combines public exhibitions with scientific and educational work, regularly collaborating with marine biologists and research institutions on conservation and aquatic research.

The arrival of sea angels is considered a significant event for marine researchers and aquarium specialists alike, as maintaining the species in captivity is exceptionally difficult due to its sensitivity to temperature, water quality, and feeding conditions.